After graduating BSc Dip Ed. from Sydney University in 1968 at age 20, I taught science in NSW schools for 40 years. The videos were created to help students enjoy learning science and to build basic knowledge.
For proper sequential learning, do the chemistry videos in this order: Elements 1-4, Radicals, Valencies, Naming compounds, Writing compound formulas, Chemical compound formulas 2, Crystal bonding. My website is www.timesaversscience.com.au and has free formula and equations pdf downloads to practice skills . They are aimed at years 5-11.
The Zealandia video describes how NZ formed over 600 million years. Bondi Excursion and Bundeena Geology videos are both excursion guides. I am a member of the Australian geological society.